Electrical apparatus



Aug. 4, 1936. QHAGAN 2,049,923

ELECTRICAL APPARATUS Original Filed Nov. 13, 1929 INVENTOR Patented Aug. 4, 1938 ELECTRICAL APPARATUS Berna-rd E. QHagan, Swissvale, Pa., assignor to The Union Switch & Signal Company, SWISS- vale, Pa, a corporation of Pennsylvania,

Application November 13, 1929, Serial No. 406,883 Renewed January 11, 1936 28 Claims.

My invention relates to'electrical apparatus, and particularly to apparatus for controlling an electric motor, such as a railway switch operating motor or the like, from a remote point.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view illustrating one form of apparatus embodying my invention. 7

Referring to the drawing, the reference character A designates a railway traffic controlling device here shown as a track switch of the usual form operated, through any suitable .form of mechanism, by a motor lvi comprising an armature l and a field 2. Associated with the switch A is a circuit controller, designated by the reference character E, and comprising a contact 3-5 which is closed at all times except when the switch occupies its full normal position, in which it is illustrated in the drawing, and a contact 34 which is closed at all times except when the switch occupies its full reverse position. The switch A also operates a pole-changer designated by the eference character H.

The motor M is controlled jointly by a polarized relay F which may be located adjacent the switch, and by a manually operable lever L which may be one of a number of such levers in an interlocking machine located at a point remote from the switch, such for example as in an interlocking cabin. Lever L is capable of assuming a plurality of different positions indicated by broken lines in the drawing and designated by the reference characters N, B, D and R. Associated with the lever L are a plurality of contacts adjacent each of which is a letter or letters which correspond to the lever positions for which the corresponding contact is closed. For example, contact i5 is closed only when the lever L is in the B position. Similarly, contact 63 is closed when lever L is in the R position, the D position, or any position intermediate these two. Also associated with the lever L is a contact 66 which is closed when the lever L is intermediate the B or D positions, but which is opened when the lever occupies its B or D positions, or any position between its N and B or D and R positions.

Attached to the lever L is a locking segment 6 co-operating with a latch l operated bya magnet 8. As shown in the drawing, the lever is in the N position. If the operator attempts to move the lever towards the R position, a projection G on the underside of the segment 6 will engage the latch l and prevent movement of the lever to the energized to permit the projection 6 to pass the latch 1 to allow the lever to assume the B position, and must again be energized to permit the shoulder 6 to pass the latch 1 to allow the lever to move to its normal position.

The magnet 8 is provided with two circuits which are controlled by the usual polarized indication relay K and by contacts on the lever L. When relay K is energized inthe normal direction, so that its polar contacts are swung to the left, the first circuit for magnet 8 is closed provided lever L is in the B position, and current flows from one terminal X of a suitable source of current not shown in the drawing through wire 9, front contact ll] of relay K, wire ll, normal contact I2-I2 'of relay K, wire 13, contact l3 of lever L, wire l4, winding of magnet 8, and wire 15, back to the other terminal Y of the source. When relay K is energized in the reverse direction, so that its polar contacts are swung to the right, however, the second circuit for magnet 8 is closed provided lever L is in the D positi0n, this circuit passing from terminal X, through wire 9, front contact In of relay K, wire H, reverse contact I 2-l2 of relay K, wire it, contact N5 of lever L, wires l1 and I4, winding of magnet 8, and wire l5 to terminal Y.

Relay K is supplied with'current over the same line wires which supply current to the motor M, and this supply is controlled by contacts on the lever L and by the pole-changer H in such manher that this relay will always indicate the position of the switch, regardless of the position of the lever, as will be explained hereinafter.

As shown in the drawing, switch A occupies its normal position. Contact 34 of circuit controller E and contacts hl l i and 5555 of pole-changer H are therefore closed, while contact 3-5' of circuit controller E and contacts 46-44 and 55---55 of pole-changer H are open. Lever L occupies its N position. A circuit is therefore completed for relay F over which current of what I will term normal polarity flows from a v of lever L, and wires 21 and 28 back to battery G. Relay F is therefore energized in its normal direction so that its front contact 30 and normal contact 3I3l are closed. Since lever L occupies its N position and since contacts 44-44 and 5555 of pole-changer H are closed, a circuit is also completed for relay K, and current flows from battery G through wires I8 and I9, NB contact I9 of lever L, wire 24, line wire 20, wires 42 and 43, contact 4444 of pole-changer H, line wire 45, Wire 46, NB contact 4'! of lever L, wires 41 and 48, winding of relay K, wires 49 and 52, NB contact 52 of lever L, wire 53, line wire 54, contact 5555 of pole-changer H, wires 5? and 55, line wire 26, NB contact 2'1 of lever L, and wires 21 and 28 back to battery G. Relay K is therefore energized in its normal direction.

Magnet 8 is de-energized because the first circuit for this magnet is opened at contact l3- of lever L and the second circuit for this magnet is open at contact l6 ofilever L and" reverse contact I2---l2 of relay K.

In explaining the operation of the apparatus,'I will first assume that it is desired to move switch A from its normal position to its reverse position. To accomplish this result, lever L is moved from its N position toward its R position. During this movement, when the lever reaches its B position, contact l3 closes and completes the first circuit previously traced for magnet 8 'so that magnet 8 becomes energized; but, as soon as the lever passes its B position, contact l3 opens and interrupts this first circuit, so that magnet 8 again becomes de-energized. Furthermore, as soon as the lever passes its B position, contacts 21 19*, 41 and 52 are all opened and contact 66 becomes closed; When contacts 2%, l9 47 and 52 are opened, the circuit previously traced for relay K is opened, and when contact 56% becomes closed, the winding of relay K is short-circuited, so that relay K becomes de-energized. Both circuits for magnet 8 are then also opened at front contact ii) of relay K, and it will be apparent, therefore, that the latch l is normally free to pass the projection 6 of the segment 5. If, however, the magnet 8 should beenergized for any reason, the movement of the lever will be arrested just after the lever passes its B position by engagement of the latch 1 with the projection 6 of segment 6. When the lever reaches its D position, contact 66 is opened, and contacts 51 60 58 63 and 16 all become closed. When contact (it is opened, the short circuit for the winding of relay K is removed, and when contacts 5l ,'60 50 and 63 become closed, another circuit for relay K is closed which passes from battery G through wires l8 and 5?, RD contact 5'7 of lever L, wire 58, line wire 26, wires 56 and 61, contact 5555 of pole-changer H, line wire 54, wire 64, RD contact 53 of lever L, wires 63, 62 and 48, winding of relay K, wires 49 and BI, RD contact 59 of lever L, wire 50, line wire 45, contact 4444 of pole-changer H, wires 43 and 42, line wire 28, wire 59, RD contact 60 of lever L, and wires 60 and 28 back to battery G. The contacts 51*. 60 59 and 63 are so arranged that the current which is supplied'to relay K over this circuit is of normal polarity, and relay K therefore becomes energized in its normal direction so that its front contact l0 and normal contact l2-,--I2 are closed. When contacts 51*- and 6!) become closed, a circuit is also completed for relay F which passes from battery G'through .wires l8 and 51, RD contact. 51% of lever L, wire 58, line wire 26, wires 25 and 23, winding of relay F, wires 22 and 2|, line wire 20, wire 59, RD contact 69 of lever L, and wires 68 and 28 back to battery G. The current supplied to relay F over this circuit is of reverse polarity, and relay F therefore opens its normal contact 3i3| and closes its reverse contact 3|-3l When reverse contact 3I-3| of relay F becomes closed, motor M is supplied with current from battery G through wires 18 and 51, contact 57 of lever L, wire 58, line wire 26, wires 25 and 39, armature I of motor M, wire 38, asymmetric unit 49, wire 35, field 2 of motor M, wire 35, asymmetric unit 4!, wire 33, contact 34 of circuit controller E, wire 68, reverse contact 3l3l of relay F, wire 69, front contact 30 of relay F, wires 29 and 2|, line wire 20, wire 59, contact 68 of lever L, and wires 60 and 28 back to battery G. Motor M therefore becomes energized, and moves switch A from its normal position towards its reverse position. As soon as the switch starts to move away from its normal position, the circuit last traced for relay K is opened at contacts 44-44 and 5555 of pole-changer H, and this relay is subsequently short-circuited at pole-changer H until the switch reaches its full reverse position by means of a wire 51 which is connected between two contact segments 44 and 55 of pole-changer H, thereby insuring that relay K will be de-energized while the switch is in transit, and thus de-energize magnet 8 so that movement of the lever L past its D position is prevented under these conditions. When the switch reaches its full reverse position, however, contacts 44--44 and 55:55 of pole-changer H become closed and complete another circuit for relay K which passes from battery G through Wires l8 and 51, contact 57 of lever L, wire 58, line wire 26, wire 56, contact 44-44 of pole-changer H, line wire 45, wire 58, contact 58 of lever L, wires GI and 49, winding of relay K, wires 48, 62 and 63, contact 63 of lever L, wire 64, line wire 54, contact 55-55 of pole-changer H, wires 78 and 42, line wire 28, wire 59, contact 68 of lever L, and wires 68 and 28 back to battery G. The current supplied to relay K over this latter circuit is of reverse polarity and relay K therefore becomes energized in its reverse direction so that its reverse contact l2l2 becomes closed. Since contact l6 of lever L is now closed, current is then supplied to magnet 8 over the second circuit previously traced for this magnet and magnet 8 therefore becomes energized and lifts latch I out of engagement with the shoulder 6 thereby permitting the movement of lever L to its full reverse position. When the lever L' reaches its full reverse position, contact w of lever L is then open and magnet 8 again becomes de-energized. Since the switch A is now in its full reverse position, the circuit previously traced for motor M is opened at contact 34 of circuit controller E, and motor M is therefore de-energized.

When the switch occupies its reverse position, it may be restored to its normal position by moving lever L from its R position to its N position. When the lever is moved to its D position, the magnet8 again becomes energized due to the circuit for magnet 8 which is then closed at contact l6 of lever L, but as soon as lever L is moved past the D position, this circuit is again opened and magnet 8 becomes deenergized. Furthermore, as soon as the lever L is moved past the D position, all circuits for relays F and K are opened, and the winding of relay K is short-circuited by contact 66 this winding remaining short-circuited by this contact until justibefore the lever reaches its B position. As pointed out hereinbefore, when relay K is de-energized, both circuits for magnet 8 are then open at front contact ill of relay K, and it will beapparent, therefore, that the latch l is normally free topass the projection li when the lever is being moved from its R toward itsN position. When the lever has reached the B position, the closing of contacts 21 le ll and 52* complete another circuit for relay K which is similar to the circuit first traced for relay K except that this circuit now includes contacts 34M and 55-55 of polechanger H instead of contacts ll4d and 44-44 of this pole-changer, so that the current supplied to relay K over this circuit is of reverse polarity. Relay K therefore again becomes energized in the reverse direction but magnet 8 now remains de-energized because one circuitfor this magnet is open at contact i6 of lever L and the other circuit is opened at normal contact 52-42 of relay K. The movement of lever L is therefore arrested at the B position. Since contacts 2i and w of lever L are now closed, relay F again becomes energized in the normal direction and opens its reverse contact 3l- -3l and closes its normal contact 3l3i A circuit for motor M is then completed from battery G, through wires 18 and I9, contact W of lever L, wire 24, line wire 20, wires 2i and 29, front contact 30 of-relay F, wire 69, normal contact 3l--Iil of relay F, wire 32, contact 35 of circuit controller E, wire 33, asymmetric unit 34, wire 35, field 2 of motor M, wire 355, asymmetric unit 31, wire 38, armature I of motor M, wires 39 and 25, line wire 26, contact El of lever L, and wires 2! and 28 back to battery G. The current supplied to motor M over this latter circuit flows through the motor armature in the opposite direction from the current supplied to the motor over the cirouit first traced for motor M, but due to the connections of the field through the asymmetric units, the current flows throughthe field in the same direction as before, and motor M therefore operates to restore switch A to its normal position. When the switch reaches its full normal position, contact 3-5 of circuit controller E opens, thereby interrupting the circuit last traced from motor M, and discontinuing the supply of current to the motor M. Movement of the switch A to its normal position also restores the polechanger H to the position in which it is illustrated in the drawing, and since lever L now occupies its B position, relay K becomes energized in the normal direction over the circuit first traced for relay K. Magnet 8 therefore becomes energized and lifts the latch I out of engagement with the shoulder 6 of segment 6 so that the lever may then be restored to its full normal position. All parts are then restored to the positions in which they are illustrated in the drawing.

One advantage of eletrical apparatus embodying my invention is that the switch operating motor may be operated in either direction in accordance with the polarity of the current supplied to a single pair of line wires 25 and 20, and that when the motor has been operated to move the switch to one position or the other, the operation of circuit controller E automatically disconnects the motor from the source of current so that power is consumed by the switch operating motor only during the actual transit of the switch.

Another advantage of electrical apparatus embodying my invention is that, since the indication relay K is supplied with current over the-same pair .of linewires which supply current to the switch motor, and since the supply of current to the relay is pole-changed by contacts on the lever at the same time as the current supplied to the line wires 25 and 20 is pole-changed, it will be apparent that reversals of relay K can onlybe caused by operation of pole-changer H. Furthermore, due to the contact 65 on lever L and to the contact member 64 and 55 of pole-changer H, relay K is short-circuited both when the lever is between the B and D positions and when the switch occupies any position between its normal and reverse position. It follows that the lever is locked against movement except when the position of'the switch corresponds to the position of the leve, and this locking is accomplished without the necessity of the usual quick-switch customarily employed for this purpose in connection with interlocking levers used for the control of railway switches.

A further advantage of electrical apparatus embodying my invention is that since the lever may be moved freely between the B-D positions, the lever may be manipulated to successively operate. the switch towards its normal and reverse positions without moving the lever to its full normal or reverse position. This operation is sometimes desirable to break lumps of coal, accumulations of ice and so forth, that prevent complete operation of the switch on the first attempt. Also,-if,' due to some failure the magnet 8 does not become energized when the switch position is changed, the switch may be restored to its original position and the lever moved to the corresponding end of its stroke, so that the switch may be used in one position, even though the lever may not be moved to the full position corresponding to the other position of the switch.

Although I have herein shown and described only one form of electrical apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination-a pair of wires, a manually operable lever for reversibly supplying current to said wires, a polarized relay receiving current from the wires and arranged to be energized in one direction or the other according as said wires are supplied with current of one polarity or the other, a motor comprising two windings, a traific controlling device controlledby the motor in accordance with the relative polarity of the currents supplied to such windings, a circuit controller actuated bysaid device, and means controlled by said polarized relay and said circuit controller and including asymmetric units for at times connecting the windings in series across said wires in such manner that current flows always in one direction through one winding but flows in one direction or the other through the other winding according to the position of said lever.

2. In combination, two windings, a railway switch controlled by said windings in accordance with the relative polarity of the currents flowing in said windings, a pair of line wires, means for reversibly supplying current to said wires, two contacts controlled in accordance with the position of said switch, a polarized relay receiving current from'said line wires, and means controlled jointly by said polarized relay and said two contacts and including asymmetric units for supplying current from the wires to one winding always in the same direction and to the other winding in one direction or the other depending upon the polarity of the current supplied to the wires.

3. In combination, a railway switch, a motor for operating said switch and comprising a field and an armature, two contacts controlled by said switch, a manually operable lever having two positions, four asymmetric units, two line wires, means for supplying said line wires with current of one polarity when said lever occupies one position and with current of the other polarity when said lever occupies the other position, a polarized relay receiving current from said line wires and having a normal contact which is closed when said wires are supplied with current of said one polarity and a reverse contact which is closed when said line wires are supplied with current of said other polarity; a first circuit including said line wires, said armature, said field, two of said asymmetric units, one of said switch controlled contacts, and thereverse contact of said relay; and a second circuit including said line wires, said armature, said field, the remaining two asymmetric units, the other switch controlled contact, and the normal contact of said relay.

4. In combination, a .device movable between a first and a second position, a motor for operating said device and comprising two windings, a circuit controller operated by said device and having a first contact which is closed at all times except when said device occupies said first position and a second contact which is closed at all times except when said device occupies said second position, two wires, a manually operable lever for reversibly supplying current to said wires, a polarized relay receiving current from said wires and having a normal contact which is closed whensaid wires are supplied with current of one polarity and a reverse contact which is closed when said wires are supplied with current of the other polarity, means for constantly connecting one terminal of one winding with one said Wire, a first and second asymmetric units connected in series across the terminals of the other winding, means for constantly connecting the common terminal of said first and second asymmetric units with the other terminal of said one winding, a third and fourth asymmetric units connected in series across said other winding, means including said first contact and said normal contact for at times connecting the common terminal of said third and-fourth asymmetric units with the other said wire, and means including said second contact and said reverse contact for at other times connecting the common terminal of said third and fourth asymmetric units with said other wire.

5. In combination, a pair of line wires, a manually operable lever, means controlled by said lever for reversibly, supplying current to said line wires, a railway switch movable between two extreme positions, means receiving current from said line wires for moving said switch to one extreme position or the other according as said line wires are supplied with current of one polarity or the other, a pole-changer operated by said switch, and a polarized indication relay receiving current from said line wires and controlled by said lever and said pole-changer in such manner that when the polarity of the current supplied to said line wires is reversed by said lever the polarity .of the current supplied to said relay remains unchanged unless said poleelectric motor comprising an armature and a field, a'railway switch controlled by said motor in accordance with the relative polarity of the currents flowing in said field and said armature, means for supplying current to said field from said wires always in the same direction and to said armature in one direction or the other depending upon the polarity of the current in said wires, a pole-changer controlled by said switch, and an indication relay receiving current from said wires and controlled by. said pole-changer and said lever in such manner that when said lever is operated to reverse the polarity of the current supplied to said wires the polarity of the current supplied to said relay remains unchanged unless said pole-changer is subsequently reversed.

'7. In combination, a railway switch, a manually operable lever having four positions; a pair of line wires, means for supplying the line wires with current of one polarity when'the lever occupies a first or a second position and for supplying the line wires with current'of the other polarity when the lever occupies a third or a fourth position, means efiective when the line wires are supplied with current of one polarity to move the switch to its normal position, means effective when the line wires are supplied with current of the other polarity to move the switch to its reverse position, a latch for preventing movements of the lever from the second to the first position and for preventing movements of the lever from the third to the fourth position a polarized indication relay having normal and reverse contacts, means controlled by said lever and by a normal contact of said polarized indication relay for releasing said latch when said lever occupies its second position, means controlled by said lever and by a reverse contact of said polarized indication relay for releasing said latch when said lever occupies its third position, a pole-changer controlled by said switch, and means controlled by. said lever and by said pole-changer for supplying said indication relay with current from said line wires in such manner that said relay is energized in the normal direction when and only when said lever occupies its first or second position and said switch occupies its normal position but that said relay is energized in the reverse direction when and only when said lever occupies its third or fourth position and said switch occupies its reverse position.

8. In combination, a railway switch; a manually operable lever having four positions,,a pair of line wires, means for supplying the line wires with current of one polarity when the lever occupies a first or a second position and for supplying the line wires with current of the other polarity when the lever occupies a'third or a fourth position, means effective when the line wires are supplied with current of one polarity to move the switch to its normal position, means effective when the line wires are supplied with current of the other polarity to move the switch to its reverse'position, a latch for preventing movements of the lever from the second to the first position and for preventing movements of the lever from the third to the fourth position, a polarized indication relay having normal and upon the polarity of the current su plied to said reverse contacts, a first contact on said lever arranged to be closed when and only when said lever occupies its second position, a second contact on said lever, arranged to be closed when and only when said lever occupies its third position, means controlled by a normal contact of said polarized indication relay and said first contact for at times releasing said latch and by a reverse contact of said polarized indication relay and said second contact for at other times re-' leasing said latch, a pole-changer controlled by said switch, and means controlled by said lever and by said pole-changer for supplying said indication relay with current from said line wires in such manner that said relay is energized in the normal direction when and only when said lever occupies its first or second position and said switch occupies its normal position and that said relay is energized in the reverse direction when and only when said lever occupies its third or fourth position and said switch occupies its reverse position.

9. In combination, a railway switch; a manually operable lever having four positions; a pair of line wires, means for supplying the line wires with current of one polarity when the lever occupies a first or a second position and for supplying the line wires with current of the other polarity when the lever occupies a third or a fourth position, means effective when the line wires are supplied with current of one polarity to move the switch to its normal position, means effective when the line wires are supplied with current of the other polarity to move the switch to its reverse position, a latch for preventing movements of the lever from the second to the first position and for preventing movements of the lever from the third to the fourth position,

a polarized indication relay having normal and reverse contacts, a first contact on said lever arranged to be closed when and only when said lever occupies its second position, a second contact on said lever arranged to be closed when and only when said lever occupies its third position, means controlled by a normal contact of said polarized indication relay and said first contact for at times releasing said latch and by a reverse contact of said polarized indication relay and said second contact for at other times releasing said latch, a pole-changer controlled by said switch, means controlled by said lever and by said pole-changer for supplying said indication relay with current from said line wires in such manner that said relay is energized in the normal direction when said lever occupies its first or second position and said switch occupies its normal position but that said relay is energized in the'reverse direction when said lever occupies its third or fourth position and said switch occupies its reverse position, and means controlled by said lever for'short circuiting the winding of said indication relay when said lever is between said second and said third position.

10. In combination, a pair of wires, means for reversibly supplying current to said wires, an electric motor comprising two windings and capable of rotation in one direction or the other wires.

11. In combination, two windings, a device controlled by said windings and capable of assuming one condition or another depending upon the relative polarity of currents flowing in said windings, a pair of wires, means for reversibly supplying current to said wires, a polarized relay receiving current from said wires, and means controlled by said polarized relay and including asymmetric units for supplying current from said wires to one winding always in the same direction and to the other winding in one direction or the other depending upon the polarity of the current.

supplied to said wires.

12. In combination, an electro-responsive device comprising two windings and capable of assuming onecondition or another depending upon the relative polarity of currents flowing in said windings, two wires, manually operable means for reversibly supplying current to said wires, means Ior constantly connecting one terminal of one winding with one said wire, a first and a second asymmetric unit connected in series across the terminals of the other winding, means for constantly connecting the common terminal of said first and second asymmetric uni-ts with the other terminal of said one winding, a third and a fourth asymmetric unit connected inseries across said other winding, and means for at times connecting the common terminalof said third and fourth asymmetric units with said other wire.

13. In combination, a device movable between two extreme positions, a pair of wires, means for reversibly supp-lying current to said wires from a given source, other means receiving current from said source-over said wires for operating said device from one extreme position .to the other according as said wires are supplied with current of one polarity or the other, and indication means responsive to the polarity of current received from said source over said wires and controlled jointly by said 'means and said device in such manner that the polarity of the current received by said indication rneans remains unchanged when the polarity of the current supplied to said wires is reversed by said means unless said device has been operated. r 1

14. In combination, a device movable between two extreme positions, a pair of wires, means for reversibly supplying current to said wires from a given source, other means receiving current from said source over said wires for operating said devices from one extreme position to the other according as said wires are supplied with current of one polarity or the other, a polechanger operated by said device, and indication means responsive to the polarity of the current received from said source over said wires and controlled jointly by said means and said polechanger in such manner that the polarity of the current received by said indication means remains unchanged when the polarity of the current supplied to said wires is reversed by said means unless said pole-changer has been operated.

15. In an indication system for railroads, a polarized line circuit, a traflic controlling device remotely controlled over said polarized line circuit, and means indicating the condition of said traffic controlling device including a polarized indication circuit receiving potential from said polarized line circuit, and means in the polarized indicationcircuit compensating for a change in polarity of said polarized line circuit. a

16. In an indication system, a source of poindication device responsive to a reversal of direction in current flow, and means connecting said device to said source of potential through said plurality of pole changing means in series, whereby operation of an odd number of pole changing means reverses direction of current flow in said device, and whereby operation of an even number of pole changing means does not reverse the direction of current flow in .said device.

17. In a control system for railroad track switches, a track switch, a switch machine for operating said track switch, point detector contacts jointly'operated by said track switch and said switch machine, manually operable control and indication contacts, a source of potential, a control relay for governing said switch machine, a circuit for said control relay from said source of potential through said control contacts, an indication relay, a circuit for said indication relay from said source of potential through said control contacts, said point detector contacts and said indication contacts respectively in series, and circuits selected by said indication relay.

18. In an interlocking system, a control lever having control and indication contacts, a poweroperated track switch, a control circuit for said power-operated track switch governed by said control contacts, point detector contacts operated in accordance with the response of said poweroperated track switch, an electro responsive indicating device, an indication circuit for said electro responsive indicating device connected to said control circuit through said point detector contacts and said indication contacts, and circuits selected by said electro responsive indicating device, whereby operation of said control lever reverses the direction of current flow in said control circuit but does not reverse the direction of current flow in said electro responsive indicating device.

19. In combination, a source of electrical potential, a control relay, an indication relay, means connecting said control relay and said indication relay successively in multiple with said-source of electrical potential, means selectively reversing the polarity only with respect to said control relay, and means selectively reversing the polarity only with respect to said indication relay.

20. In a traffic controlling system, the combination with a central oflice and a distant way station, a line circuit connecting said office and way station, two polarity energy applying means and a polar relay at said oflice, means for ineluding either said energy applying means or said polar relay in said circuit and for including said polar relay in a particular polar direction in said circuit in accordance with the last polarity of current applied to said line circuit by said energy applying means, and means at said way station controlled by said energy applying means and for controlling said polar relay over said line circuit.

21. In a trafiic controlling system, the combination with a central oflice and a distant way station, a line circuit connecting said ofiice and way station, two polarity energy applying means and a polar relay at said ofiice, means for including either said energy applying means or said polar relay in said circuit and for including said polar relay in said circuit in accordance with the last polarity of current applied to said line circuit by said energy applying means, and means at said way station controlled by said energy applying means and for controlling said polar relay over said line circuit.

tential, a plurality of pole changing means, an'

22. In a traiiic controlling system, the combination with a central oflice and a distant way station, a line circuit connecting said office and way station, two polarity energy applying means and a polar relay at said ofiice, means for including either said energy applying means or said polar relay in said circuit and for including said polar relay in a particular polar direction in said circuit in accordance with the last polarity of current applied to said line circuit by said energy applying means, and traflic controlling means at said way station controlled by said energy applying means and including means for controlling said polar relay in accordance to the operated condition of said traflic controlling means.

23. In combination, means for controlling a switch machine in accordance with the polarity of current of a particular character transmitted over a line circuit from a central office and for transmitting an indication to said central ofiice by current of the same character over said line circuit and having a polarity corresponding to the position of said switch machine.

24. In combination, a railway track switch, a pole-changer operated in conjunction with said switch and'arranged to occupy a normal or a reverse position according as said switch is in its normal or its reverse position, a manually operable lever having normal and reverse contacts closed when said lever is moved to a normal or a reverse position respectively, normal and reverse control circuits for said switch including said normal and reverse lever contacts respectively, means controlled by said normal and reverse control circuits for operating said switch to normal and reverse positions, indication means for indicating the normal and reverse positions of said switch, and normal and reverse control circuits for saidindication means controlled by said polechanger and including said normal and reverse lever contacts respectively.

25. In combination, a railway track switch, manually controlled normal and reverse switch circuits for controlling operations of said switch to normal and reverse positions respectively, indication means selectively responsive to current of normal and reverse polarities for indicating normal and reverse positions of said switch, and manually controlled normal and reverse indication circuits for energizing said indication means by current of normal and reverse polarities controlled by said switch in normal and reverse positions respectively and supplied from said manually controlled normal and reverse circuits.

26. In combination, a railway track switch, control apparatus selectively responsive to current of normal and reverse polarities for controlling operations of said switch to normal and reverse positions respectively, indication means selectively responsive to current of normal and reverse polariti s controlled by said switch for indicating normal and reverse positions respectively of said switch, and manually controllable means for supplying current of normal and reverse polarities for energizing said control apparatus and for energizing said indication means through pole-changing means controlled by said switch. 7

27. In combination, a railway track switch, control apparatus selectively responsive to current of normal and reverse polarities for controlling operations of said switch to normal and reverse positions respectively, a manually controllable device, circuits controlled by said manually controllable device for energizing said control apparatus by current of normal or reverse polarity according as said manually controllable device is in a first or a second position, indication means selectively responsive to current of normal and reverse polarities for indicating normal and reverse positions respectively of said'switch, and circuits controlled by said manually controllable device and by said switch for energizing said indication means by current of normal or reverse polarity according as said switch is in the normal or the reverse position but independently of the position of said manually controllable device.

28. In combination, a railway track switch, a normal control wire and a reverse control wire for said switch, means located at a remote point for connecting one or the other of said wires with one terminal of a source of current, a polarized indication relay, and means operating when said switch is in normal position to connect one terminal of the winding of said relay with said one terminal of said source through said normal wire and the other terminal of the relay winding with the other terminal of said source, said means operating when the switch is in reverse position to connect the second terminal of said relay winding with said one terminal of said source through said reverse wire and the first terminal of the relay winding with said other terminal of said source.

BERNARD E. OHAGAN 

